1. Field of the Invention
This invention relates to the analysis of seismic data and specifically to an electronic system for automatically producing horizons from processed seismic data.
2. Description of the Prior Art
In the past, human interpreters solved the problem of producing horizons of three-dimensional seismic events mentally, using paper and colored pencils, or computer graphics, to draw a seismic event as it intersects successive two-dimensional seismic sections of a data volume. Once two-dimensional events along the three-dimensional surface have been picked, the two-way times to each of the 2-D events are determined and a variety of different types of maps are drawn to illustrate information about the event surface. The primary disadvantage of this approach is that it is very time-consuming and tedious for the human interpreters. The task of drawing maps or horizons of event surfaces is easily automated once the events are picked, but the picking is very time-consuming. A prior art method for picking and mapping events in 2-D seismic sections has been achieved. This previous approach to determining significant changes by amplitude zero-crossings in seismic traces essentially amounts to an assertion that the significant changes of interest are primarily determined by points where the trace changes sign. This technique is not well-suited to mapping seismic events whose amplitudes change signs.